Staybolt



Sept. 10, 1935. J KINDERVATER STAYBOL'T Filed March 6, 1935 INVENTOR Jill/us lll'ndervbr BY 6) ATTONEY Patented Sept. 10, 1935 STAYBOLT Julius Kindervater, Richmond, Va., assignor to American Locomotive Company, New York, N. Y., a corporation of New York Application March 6, 1935, Serial No. 9,532

'7 Claims.

This invention relates to improvements in staybolts for boilers and is especially directed to such bolts as are known in the art as flexible staybolts and used principally in connection with locomotive boilers in a manner well known in the art.

An object of the invention is to provide an improved staybolt provided with an integrally formed head and a continuous bore or tell-tale hole extending throughout its length, with suitable means at the head end of the bore providing a sealing cap therefor.

Other objects of and advantages achieved by this invention will be apparent from the following detailed description of approved embodiments ,of the staybolt of the invention which are illustrated in the accompanying drawing.

In the accompanying drawing Figures 1 to 6 are views of parts of a staybolt illustrating the steps followed in the manufacture of the staybolt as well as the structure of the improved staybolt, Fig. 1 being a side elevation of the upper part of the staybolt prior to the drilling of the tell-tale hole and without its cap, Fig. 2 a view similar to Fig. 1 with the bolt turned about its axis 90 degrees and having a tell-tale hole formed therein, Fig. 3 a plan of the bolt shown in Fig. 2, Fig. 4 a vertical section of the cap, Fig. 5 a plan view of the cap, and Fig. 6 a vertical section of the bolt of Fig. 1, with its cap, the right side .of the cap being illustrated in its completely assembled position and the left side being illustrated in its position before being clamped to the staybolt head; Fig. 7 is a side elevation, on a reduced scale, of the completed staybolt, the parts of which are illustrated in the previously mentioned figures; Fig. 8 is a vertical sectional view of the upper part of a staybolt embodying a modified form of the present invention with its cap illustrated at the right side of the figure in its completely assembled position and at the left side in its position before being clamped to the staybolt head; and Fig. 9 is a plan view of the staybolt shown in Fig. 8.

Referring in detail to the drawing, a blank round iron is heated and upset at one end in a forging machine to the approximate shape shown in Fig. 1, to thus include a body portion I and a head 2 of semi-spherical shape and having a dovetailed or diverging tapered portion 3 formed thereon. A curved bottomed slot 4 is formed in the portion 3. After the forging machine operation, the bolt is further worked on an upright hammer and is rotated in finishing dies until the final desired form, as shown in Fig. 1, is obtained.

A bore is next drilled throughout the length of the staybolt (including the head and portion 3) providing a tell-tale hole 5 (as shown in Fig. 2) the concentricity of which is readily apparent to the operator. It is noted that in prior practice Where the bore is drilled into (and stops within) the head, from the inner end of the bolt, it is practically impossible to determine to what extent the tell-tale hole is concentric and for this reason defective bolts of this type are often not discovered until after they break or crack during use.

A sealing cap 8 is formed in a suitable doubleacting forging machine of any well-known appropriate design. In this machine a blank is punched out of a flat strip, formed and indented, in the shape shown, in one operation. The cap is of octagon shape, that is, it has eight sides 1-1 which in the initial form of the cap before assembly extend downwardly substantially perpendicularly from the top portion 8 of the cap to a point near the bottom where the cap is formed round for a purpose later to be stated. The indent above referred to provides a tongue 9 extending downward from the top portion. No finishing of the cap is necessary.

The cap is placed on the end portion 3 of the bolt with the tongue 9 extending into the slot 3 (see Fig. 6). When the cap is first applied its sides '1 are all in the position shown at the left side of this figure. A seal or washer it of suitable material, such as copper, is interposed between the top portion 8 and the top of the bolt portion 3. The two parts are placed in a swaging machine or press and the lower portion of the sides l-l are forced inwardly from the top to the bottom slantingly, while cold, in engagement with the slanting surface of the portion 3, as shown at the right side of Fig. 6, effecting a closing of the cap on the end portion 3 and a drawing downward of the cap to a sure tight grip where the seal is applied. During the swaging operation, the extra material afforded by the circular base portion of the cap is forced inwardly to effect a re-shaping of the cap from the shape shown at the left in Fig. 6 to substantially that shown at the right. The octagon shape of the cap permits the bolt to be turned during the assemblage of the bolt in a boiler and the tongue and slot connection between the cap and bolt head prevents any relative turning movement between these parts.

In Figs. 8 and 9 is illustrated another embodiment of this invention wherein the staybolt, while similar to that first described in general principle, is modified as to certain details. More particularly for the tapered end portion 3 is substituted in the modified structure the mushroomshaped portion H. The cap I2 in this embodiment of the invention includes a reduced squared end portion l3 and a cylindrical portion l 4 joined thereto which, in assembled position, tightly grips the portion H. The original shapeof the portion M, as when first placed on the portion H, is shown at the left side of Fig. 8 and its shape after the closing operation is shown at the right side of this figure. A seal or washer l5, of suitable material, such as copper, is inserted between the cap 12 and the portion l I before the closing operation, similarly as described with reference to the seal Hi.

It will be apparent that a staybolt is provided which has all the desirable attributes of a staybolt of this type with regard to form and structure and wherein the true concentricity of the tell-tale hole is assured.

While certain approved embodiments of the staybolt have been illustrated and described, it will be understood that various changes and modifications in the form, structure and ar rangement of the staybolt parts may be resorted to without departing from the spirit of the invention-and it will be understood that all such changes and modifications are contemplated as a part of this invention as defined in the appended claims.

The invention claimed and desired to be secured by Letters Patent is:

1. A staybolt for boilers comprising a body portion having a substantially semi-spherical head adapted to seat said staybolt integrally formed on an end thereof, with a longitudinal bore extending through said body portion and said head; and a separate cap tightly secured on said head forming a rigid connection therewith thereby providing a fluid-tight closure for said bore at the head end thereof.

2. A staybolt for boilers comprising a body portion having a head integrally formed thereon and an integral projection extending from said head, with a longitudinal bore extending through said body portion, head and projection; and a separate cap secured to and incasing said projection, closing said bore at the projection end thereof.

3. A staybolt for boilers comprising a body portion having a semi-spherical head integrally formed on an end thereof and an integral pro.-

jection extending from said head, with a longi tudinal bore extending through said body portion, head and projection; and a separate cap fitted over said projection and having its side walls in clamped engagement with the side walls of said projection, closing said bore at the projection end thereof.

4. A staybolt for boilers comprising a body portion having a semi-spherical head integrally formed on an end thereof and a divergingly tapered integral projection extending from said head, with a longitudinal bore extending through said body portion, head and projection; and a separate cap fitted over said projection and having its side walls in clamped engagement with the tapered side walls of said projection, closing said bore at the projection end thereof.

5. A staybolt for boilers comprising a body portion having a substantially semi-spherical head adapted to seat said staybolt integrally formed on an end thereof, with a longitudinal bore extending through said body portion and head; a separate cap tightly secured to said head forming a rigid connection therewith thereby providing a fluid-tight closure for said bore at the head end thereof; and means holding said cap against turning movement relative to said. head.

6. A staybolt for boilers comprising a body portion having a head integrally formed at an end thereof and an integral projecting member extending from said head, with a longitudinal bore extending through said body portion, said head and said projecting member; and a separate cap member engaging said projecting member and closing said bore at the projecting member end thereof, one of said members having a slot formed therein and the other of said members having a tongue formed thereon and extended into said slot to prevent relative turningmovement of said members.

7. A staybolt for boilers comprising a body por-. tion having a head integrally formed on an end thereof and an integral projection extending from said head, with a longitudinal bore extending through said body portion, head and projection; and a cap secured to said projection closing said bore at the projection end thereof and shaped to provide means for gripping said I staybolt to turn said staybolt about its axis.

JULIUS KINDERVA'IER. 

